Microsoft nails down Windows Phone 7 data-uploading issue

Third-party software is mostly responsible for a Windows Phone 7 issue that has caused, for some users, megabytes of mysterious data uploading over 3G, Microsoft said today.

Last week, Microsoft said it was investigating claims that its new mobile operating system was sending, by at least one account, up to 50GB 50MB of unidentified data per day, unprompted by the user. Even when connected to a Wi-Fi network, the Windows Phones reportedly used 3G, potentially inflating users’ phone bills. (Updated 9:54 a.m., Jan. 20: Corrected MB/GB typo.)

A Microsoft spokesperson, responding to a seattlepi.com request for updated information, sent the following statement:

We have determined that a third-party solution commonly accessed from Windows Phones is configured in a manner that potentially causes larger than expected data downloads. We are in contact with the third party to assist them in making the necessary fixes, and are also pursuing potential workarounds to address the configuration issue in case those are needed. At this point in our investigation, we believe this is responsible for most of the reported incidents.

We are investigating additional potential root causes for the remainder of the reports.

A small (low single-digit) percentage of Windows Phone customers have reported being affected.

We are continuing to investigate this issue and will update with additional information and guidance as it becomes available.

The spokesperson did not immediately respond to a request for more detail on the third party.